Refrigerant composition for replacing chlorodifluoromethane

Abstract

A refrigerant composition that can be a substitute for chlorodifluoromethane (HCFC-22) comprises: (a) a first constituent of difluoromethane, (b) a second constituent of 1,1,1-trifluoroethane, (c) a third constituent of 1,1,1,2,3,3,3-heptafluoropropane and (d) a fourth constituent selected from the group consisting of isobutane, 1,1,1,2,3,3-hexafluropropane and butane; or comprises: (a) a first constituent of difluoromethane, (b) a second constituent of 1,1,1,2-tetrafluoroethane, (c) a third constituent of 1,1,-difluoroethane, and (d) a fourth constituent selected from the group consisting of 1,1,1,2,3,3,3-heptafluoropropane, 1,1,1,2,3,3-hexafluropropane and butane.

What is claimed is:  
     
       1. A refrigerant composition comprising: 
       (a) 40-70 wt. % of difluoromethane as a first constituent,  
       (b) 10-40 wt. % of 1,1,1-trifluoroethane as a second constituent  
       (c) 10-20 wt. % of 1,1,1,2,3,3,3-heptafluoropropane as a third constituent, and  
       (d) 5-15 wt. % of isobutane as a fourth constituent.  
     
     
       2. The refrigerant composition according to  claim 1 , wherein the content of the first constituent is in the range of 40-55 wt. % and the content of the second constituent is in the range of 20-40 wt. %. 
     
     
       3. The refrigerant composition according to  claim 2 , wherein the contents of the first, second and fourth constituents are in the ranges of 50-70 wt. %, 10-30 wt. % and 5-12 wt. %, respectively.